Laminated sheet



Ap 8, 1947. P. ZAL.KIND 2,418,612

LAMINATED SHEET Original Filed May 14. 1935 Patented Apr. 8, 1947 LAMINATED SHEET Philip 'Zalkind, New York, N. Y.

Original application May 14, 1935, Serial No.

21,411, now Patent No. 2,274,765, dated March 3, 1942. Divided and this application February 28, 1942, Serial No. 432,769

1 Claim.

My invention relates to a combination sheet of laminar construction having a fold line and comprising a lamina of metal and a non-metallic lamina, the fold line of the combination being produced'by conditioning the non-metallic lamina. This application is a division of my application Ser. No. 21,411, which was filed on May 14, 1935, now Patent No. 2,274,765, issued March 3, 1942.

As fully set forth in the above patent my invention finds utility 1n the construction of cabinets and other box-like structures as shown in my Patent No. 2,159,069 which, by virtue of utilizing walls of sheet metal combined with fiber board may be made fire-resistant, foldable, light and sturdy.

The present invention is illustrated in the accompanying drawingsin which:

Fig. 1 is a plane view of the elements of my invention showing a composite board of sheet metal and fiber backing sheets prior to folding along a score line determined by the position of the backing sheets;

Fig, 2 is a section through 2-2 of Fig. 1; and

Fig. 3 is a section similar to Fig. 2 showing the composite board after it has been folded along the predetermined score line.

With reference to the figures of the drawings, I combine non-metallic sheets I and I with a metallic sheet 3. The non-metallic sheets may be of diiierent materials from each other, and they may (as shown) beof different thicknesses, sheet I being somewhat thicker than the sheet I, as clearly shown in Figure 2. In laying up the structure, the edge of sheet I may be suitably spaced from the edge of I. Where solid material such as plywood, etc, is used, this distance should be slightly less than the thickness of the thinner of the two sheets; but where yieldable material like corrugated board provides one of the edges, spacing may be unnecessary. When the sheet is manually bent along the score line 6, the thicker of the two sheets will ride on the thinner sheet and form a tight fitting corner without strain or distortion of the non-metallic layer as clearly shown in Figure 3.

Where the material of the non-metallic layer is easily yieldable, such as corrugated board, the sheets I and I may be of the same thickness as each other, but the same efiect as that obtained 2 from sheets of two thicknesses may be secured by slightly crushing one of the sheets adjacent to the score line and for a width equal to or slightly greater than the thickness of the uncrushed sheet. By this means, the crushed portion will act in the manner of the thinner of the two sheets shown in Figure 2, and the thicker layer I will ride on top of it in bending up an angle in material between the layers.)

the manner as shown in Figure 3.

In Figure 3 I have shown prongs punched out of the metallic layer functioning. to unite the laminations. (These may be assisted by adhesive These prongs 1 pass through the non-metallic layer and are clinched over straps H made of metal or other suitable material. It will be noted that as, shown in cross-section in the upper part of Figure 1, the prongs are shaped to present a convex surface on the side adjacent to the strap II. This shape has several particular advantages. First, the prong has greater strength than would a flat prong of the same thickness of metal, and it is therefore forced more easily through the nonmetallic layer. Second, if the prong is pressed through the non-metallic layer against an unyielding backing, the arcuate shape will cause the end of the prong to bend toward the convex face when it strikes the unyielding surface, using the principle which I have disclosed in my application Ser. No. 693,841, filed October 16, 1933, now Patent No. 2,233,906, issued March 4, 1941. The prong will thereby be bent so as to clinch over the backing strap I l. l

When the two members land I of the non, metallic element are spaced apart, there may he need for further means to precisely determine the bend line as to the particular edge of said space, otherwise the bend might come indiscriminately at'the line 611, or line (lb, or intermediately. The difference in thickness of the material predetermines the bend line at the line 6b as shown.

I claim': I

As an article of manufacture, a sheet of laminar material comprising sheets of non-metallic material securely joined to a layer of sheet metal, the said sheets of non-metallic material being spaced from each other and defining a bending area for the composite sheet, and means for predetermining the abutting arrangement of the margins and edges of said non-metallic sheet v v 3 material with respect to each other and with respect tovthe layer of sheet metal when said composite sheet is folded about said predetermined bending area to a position where one of said non-metallic sheets is normal to the other, 5

said means comprising the spacing of said edges by a distance substantially equal to the thickness ofone edge, the other edge being thicker than said first edge and guiding said first edge during folding so that it engages the surface of the metallic ieyer when the fold is completed, while said other edge abuts the margin 01 the sheet which includes the first edze. v 1

, PHILIP aces The following references are of record in the Y file of this patent:

UNITED STATES PA! on I 

